Improvement in the methods of making serrated sickle-sections



UNITED STATES PATENT QFFICE.

GEORGE F. SIMONDS, OF FITCHBURG, MASSACHUSETTS, ASSIGNOR TO THE 'SIMONDSMANUFACTURING COMPANY, OF SAME PLACE.`

IMPROVEMENT IN THE METHODS 0F MAKING SERRATED SICI-(I E-SECTIONS.-

Specification forming part of Letters Patent No. 90,593, dated May 25,1869.

To all lwhom it may concern:

Be it known t-hat I, G. F. SIMONDS, of Fitchburg, in the county ofVorcester and State of Missaehusetts, have invented an Improvement inthe Manufacture of Serrated Siekle- Sections; and I do hereby declarethat the following, taken in connection with the dra-wings whichaccompany and form part of this specification, is a description of myinvention sufficient to enable those skilled in the art `to practice it.v

In serratin g blanks for sickle-sections of harvesting-machines, theindentations or teeth are made upon, and so as to exten d across, thebeveled edge of the blank, so that as the cuttingedge is ground down insharpening', the serra-- tions of the cutting-edge are preserved.

As the indentations are first cut across the upper surface of thebeveled edge of the blank, and not into the edge, like saw-teeth, theedge ofthe bevel has to be bent down, so that by facing off the edge toa plane ofthe under surface of the cutter the cutting-edge will beserrated.

The process heretofore practiced to obtain the serrated edge has been asfollows: The bevel-edged blank is placed upon a suitable hat-surfacedbed, but with its beveled edge projecting over anincline upon the bed.By successive blows of a suitable cutter the upper surface of 4eachbeveled edge is now eut or toothed, each blow of the cutter not onlymak-- ing a groove or indentation in the surface of the blank, but alsobending down the edge at the blow-given point to the surface of the in'-cline over which the edge proj eets. When this cutting has beenaccomplished the under surface of the edge of the blank will be belowthe plane of the under surface ofthe blank. Such bent-down edge is thenground off to the plane of the under surface of the plate, the edgebeing thereby formed into a serrated cuttingedge.

Sickle-sections made by this process are imperfect, in that as thecutting-edge of the cutter has to be parallel to the surface of theincline down to which the edge is to be bent, the part of the bevelededge `back of the bend so formed is not out to the same depth as thepart of the edge bent down, in consequence of which the serrations ofthe cutting-edge diminish in depth as the edge of the section is groundback in sharpening; and, also, in that as the bending action of thecutter does not extend to the point of the section, the edge of thesection adjacent to such point protrudes beyoi 1d the points of thecutting-teeth, (when the edge has been ground off,) thereby impairingthe cutting action of the section.

To obviate these objections I support the beveled edge upon a flat bedunder the action ofthe cutter, the cutting-edge of the cutter beingparallel to the surface of the beveled edge ofthe blank, thus causingthe grooves to be cut to a uniform depth throughout each; and havingthus effected the cutting, I remove the blank from the flat bed, andbend down the whole edge of the bevel at once, (by any suitablemechanism,) after which the bent edge is ground off .to a plane with thebottoni surface of the plate, thus making the serrated cutting-edge.Itis in this process for producing the serrated edge that my improvementconsiststhat is to say, a process consisting in first cutting thegrooves across the beveled surfaces of the section, next bending down atone operation the edge of the bevel, and, lastly, grinding off the edgethus bent down to a plane with the under surface of the blank plate.

The drawings represent a sickle-section made in accordance with myprocess, and also a section made by the old process, above described.

A shows a top view of one of my sections finished. B is a section,showing the edge after being bent and before being ground 0E. C is asimilar section, showing the iinished edge. D is a top view of theiinished section made by the old process described. E shows the edge ofsuch section before it is ground off.

In my process, the blank being supported at its beveled edge upon a fiatbed, each groove .is cut to a uniform depth throughout, as seen at A,and at B and C, and the entire length of edge on either side ofthe pointofthe section being then bent down, as seen at B, and the bent edgebeing then ground down to the plane of the under surface of the plate,the cuttingedge will be left as seen at A and C, or so that, as theplate is reduced in thickness in resharpening, the serrations or teethof the cutting-edge arekept of the same size, whereas,

doWnthe Whole edge of the bevel, and, finally,

grinding oi the edge, substantially as described.

2. Sickle-sections made by the improved process described.

GEO. F. SIMONDS.

Witnesses:

J. B. CROSBY, FRANCIS GOULD.

